Dispensing instrument for fluid monitoring sensors

ABSTRACT

A sensor dispensing instrument is adapted to receive a generally circular sensor pack containing a plurality of blood glucose sensors. Each of the sensors are disposed in sensor cavities, each of which is in fluid communication with a corresponding desiccant cavity and has a support wall that assists in directing the sensor as its being ejected from the cavity. The sensor pack is loaded on an indexing disk in the instrument such that when a slide actuator on the instrument is moved toward a testing position, a feed mechanism engaged by the slide actuator moves a knife blade thereon toward one of the sensor cavities. The knife blade pierces a portion of a foil covering the sensor cavity and engages the sensor disposed in the cavity to thereby eject the sensor from the sensor cavity. The continued sliding of the slide actuator toward its testing position results in the sensor being completely ejected from the sensor cavity and disposed in a testing position with a testing end of the sensor projecting from the instrument. Once the blood analyzing test is completed, the slide actuator is moved in the opposite direction towards its standby position. As the slide actuator is moved away from its testing position, the indexing disk with the sensor pack thereon is rotated so that the next one of sensor cavities is positioned so that the sensor therein can be used for the next blood glucose test that is to be performed. The instrument includes circuitry to obtain test data from the sensor pack and to display testing data.

This application is a continuation-in-part of application Ser. No.08/372,304 filed on Jan. 13, 1995, now U.S. Pat. No. 5,575,403.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a fluid monitoring system,and, more particularly, to a new and improved instrument for handlingmultiple sensors that are used in analyzing blood glucose or otheranalytes contained therein.

2. Description of the Prior Art

People suffering from various forms of diabetes routinely need to testtheir blood to determine the level of blood glucose. The results of suchtests can be used to determine what, if any, insulin or other medicationneeds to be administered. In one type of blood glucose testing system,sensors are used to test a sample of blood.

Such a sensor may have a generally flat, rectangular shape with a frontor testing end and a rear or contact end. The sensor contains biosensingor reagent material that will react with blood glucose. The testing endof the sensor is adapted to be placed into the fluid being tested, forexample, blood that has accumulated on a person's finger after thefinger has been pricked. The fluid is drawn into a capillary channelthat extends in the sensor from the testing end to the reagent materialby capillary action so that a sufficient amount of fluid to be tested isdrawn into the sensor. The fluid then chemically reacts with the reagentmaterial in the sensor with the result that an electrical signalindicative of the blood glucose level in the blood being tested issupplied to contact areas located near the rear or contact end of thesensor.

In order to couple the electrical signals produced at the sensorcontacts to monitoring equipment, the sensors need to be inserted intosensor holders prior to the sensor end being placed into the fluid beingtested. The holders have corresponding mating contact areas that becomecoupled to the contacts on the sensor when the sensor is inserted intothe holder. Consequently, the holders act as an interface between thesensor and monitoring equipment that accumulates and/or analyzes thetest results.

Prior to being used, the sensors need to be maintained at an appropriatehumidity level so as to insure the integrity of the reagent materials inthe sensor. Sensors can be packaged individually in tear-away packagesso that they can be maintained at the proper humidity level. Forinstance, blister type packaging methods could be used. In thisconnection, the packages can include desiccant material to maintain theproper humidity or desiccate level in the package. In order for a personto use an individual sensor for testing blood glucose, the package mustbe opened by tearing the seal. Alternatively, some packages require theuser to exert force against one side of the package resulting in thesensor bursting or rupturing the foil on the other side. As can beappreciated, the opening of these packages can be difficult. Moreover,once the package is opened, the user needs to be sure that the sensor isnot damaged or contaminated as it is being placed into the sensor holderand used to test the blood sample.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a new andimproved sensor pack of multiple sensors used in testing blood glucoseand a dispensing instrument for handling the sensors contained in suchsensor packs. In particular, objects of the present invention are toprovide a new and improved fluid sensor dispensing instrument handlingdevice that is adapted to receive a sensor pack containing a pluralityof fluid sensors so that individual sensors can be selectively placed ina testing position when a feed actuator on the sensor dispensinginstrument is moved to a testing position and to automatically index thesensor pack while the feed actuator is being returned to its standbyposition so that another one of the sensors can be placed into a testingposition; to provide a new and improved fluid sensor dispensinginstrument having a cutting device pivotally mounted on a driver devicewith the cutting device ejecting sensors from a sensor pack so as toposition the ejected sensor in a testing position and being displacedfrom the sensor pack as the driver device is returned to a standbyposition; to provide a new and improved fluid sensor dispensinginstrument having a sensor pack with a plurality of cavities forindividual sensors with each of the cavities having a support surfacefor facilitating the ejection of the sensor from the sensor cavity; toprovide a new and improved fluid sensor dispensing instrument thatprovides a contact device to couple individual sensors to dataprocessing equipment in the sensor dispensing instrument so that datafrom the individual sensors can be displayed; to provide a new andimproved fluid sensor dispensing instrument having a calibrationmechanism disposed in one hinged portion of the dispensing instrumentthat is interconnected to data processing equipment in another hingedportion of the dispensing instrument by a somewhat flexible connectordisposed in a serpentine configured channel; and to provide a new andimproved fluid sensor dispensing instrument having holding devices thatintermate with notches on a sensor pack to properly position the sensorpack with respect to an indexing device and to insure that the sensorpack rotates with the indexing device.

In accordance with these and many other objects of the presentinvention, the present invention is embodied in a sensor dispensinginstrument that is adapted to receive a sensor pack containing aplurality of blood glucose sensors. Each of the sensors has a generallyflat, rectangular shape with a front testing end through which fluid isdrawn so as to react with a reagent material in the sensor and anopposite rear, contact end. The sensor pack includes a generallycircular shaped base portion in which is formed sensor retainingcavities or depressions. Each of the sensor retaining cavities isadapted to receive one of the sensors and is in fluid communication witha corresponding desiccant cavity in which is disposed desiccantmaterial. The desiccant material is placed in the cavity to insure thatthe corresponding sensor cavity is maintained at an appropriate humidityor desiccate level so that the reagent material in the sensors will notbe adversely affected prior to the sensors being used. A foil is heatsealed onto the base portion about the entire outer peripheral edge ofthe base portion and about the entire perimeter of each set of sensorretaining and desciccant cavities to seal the sensor retaining cavitiesand the desiccant cavities such that the individual sensors aremaintained in a desiccated state and isolated from each other. As aresult, the opening of one sensor cavity will not affect the desiccatedstate of any other sensor cavity.

Each of the sensor cavities has a support wall on which the individualsensor lies when the sensor is disposed in the sensor cavity. Thesupport wall extends in a radial direction from adjacent the peripheraledge of the base portion toward a center of the base portion. In orderto assist in the ejection of the sensor from the sensor cavity, thesupport wall includes a sloped or inclined portion that is sloped towardthe foil sealing the base portion in a direction toward the peripheraledge of the base portion. The sensor pack additionally includes a seriesof notches formed along the outer circumferential edge of the sensorpack with each of the notches corresponding to one of the sensorcavities.

The sensor instrument includes an outer housing having an upper case anda lower case with the upper and lower cases being pivotable with respectto each other in a clam shell fashion so that the sensor pack can bepositioned in the housing on an indexing disk disposed in the housing.With the sensor pack loaded in the housing, a slide latch on a slideactuator disposed on the upper case of the housing controls whether themovement of the slide actuator places the instrument in a display ordata processing mode or in a testing mode.

The instrument is placed into its display mode when the slide latch ismoved laterally and the slide actuator is pushed away from its standbyposition. When in the display mode, a person using the instrument canview data displayed on a display unit in the upper case and/or inputdata into the instrument.

The instrument is in its testing mode when the slide latch is in itsnormal position and the slide actuator is pushed towards its testingposition. A feeding mechanism engaged by the slide actuator inside theupper case of the housing also is moved from its standby position towarda testing position. The feeding mechanism includes a driver on which ispivotally mounted a knife blade and from which extends an indexing diskdrive arm. As the slide actuator is moved towards its actuated position,the driver with the knife blade thereon moves toward the testingposition of the feed mechanism and the disk drive arm travels in astraight, radially extending groove in the indexing disk such that thedisk is not rotated as the feeding mechanism is moving towards itstesting position. The knife blade has cam followers that ride on a firstportion of a cam track and under a lift spring as the driver starts tomove away from its standby position. The first portion of the track isinclined toward the sensor pack so that the knife blade is moved towardsone of the sensor cavities in the sensor pack positioned on the indexingdisk. The knife blade pierces the foil covering the sensor cavity inalignment with the knife blade and engages the sensor disposed in thecavity. As the slide actuator and the driver are pushed toward theactuated position of the actuator, the knife blade further severs thefoil covering the sensor cavity and forces or ejects the sensor out fromthe sensor cavity such that a front biased edge of the sensor burststhrough the outer foil covering the sensor cavity. As the sensor isbeing forced out of the sensor cavity, the sensor travels along thesloped support wall of the sensor cavity so that as the sensor isadvanced by the knife blade, the sensor will avoid being forced into theheat seal that affixes the foil to the base portion of the sensor pack.The force required to move the sensor through the foil is minimized bythe pointed, biased geometry of the front of the sensor so that thesensor cuts an exit hole through the foil rather than merely stretchingit.

The continued sliding of the slide actuator toward its testing positionresults in the sensor being completely ejected from the sensor cavity. Aguide disposed near the testing end of the sensor housing guides thesensor from the sensor cavity into a testing position. As this isoccurring, cam surfaces on the front of the driver engage a sensoractuator that maintains the sensor in its testing position with thetesting end of the sensor projecting out from the testing end of thehousing. The sensor actuator includes contacts that become mated withcorresponding contacts on the sensor. The sensor dispensing instrumentmay include a microprocessor or other data processing circuitry that islikewise electrically coupled to the sensor actuator so that dataobtained from the sensor when it is inserted into blood to be tested canbe processed. The processed data then can be displayed on a screen inthe upper case of the instrument or stored for use in other analyzingequipment.

Once the blood analyzing test is completed, the slide actuator is movedin the opposite direction towards its standby position. As the slideactuator is moved away from its testing position, the driver moves awayfrom the sensor actuator so that the contacts on the sensor actuatormove away from the corresponding contacts on the sensor and the sensorcan be removed from the dispensing instrument. The continued retractionof the driver results in the cam followers on the knife assembly to rideonto the lift spring so that the knife blade is moved away from thesensor pack allowing the indexing disk to advance the sensor pack. Inthis regard, the indexing disk drive arm extending from the driverbegins to travel along a curvilinearly extending groove that isinterconnected to the radially extending groove in the indexing diskresulting in the rotation of the indexing disk. The rotation of theindexing disk also results in the sensor pack being rotated so that thenext one of sensor cavities is positioned in alignment with the knifeblade so that the sensor in the sensor cavity can be used for the nextblood glucose test that is to be performed.

The dispensing instrument includes calibration circuitry with probesthat contact a label on the sensor pack when the sensor pack is mountedon the indexing disk. The calibration circuitry provides the dataprocessor with data as to the sensor pack and the tests performed withthe sensors in the sensor pack.

BRIEF DESCRIPTION OF THE DRAWING

The present invention, together with the above and other objects andadvantages, can best be understood from the following detaileddescription of the embodiment of the invention illustrated in thedrawing, wherein:

FIG. 1 is a perspective view of a blood glucose sensor dispensinginstrument embodying the present invention;

FIG. 2 is a top plan view of the blood glucose sensor dispensinginstrument of FIG. 1;

FIG. 3 is a bottom plan view of the blood glucose sensor dispensinginstrument of FIG. 1;

FIG. 4 is a perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 shown with a sensor in a testing position;

FIG. 5 is an exploded perspective view of a sensor pack used in theblood glucose sensor dispensing instrument of FIG. 1 with the foilportion of the sensor pack separated from the base portion of the sensorpack;

FIG. 6 is top view of the base portion of the sensor pack of FIG. 5;

FIG. 7 is side view of the base portion of the sensor pack of FIG. 5;

FIG. 8 is bottom view of the base portion of the sensor pack of FIG. 5;and

FIGS. 9A-9C are exploded perspective views of the component parts of thesensor dispensing instrument of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more specifically to the drawings, therein is disclosed ablood glucose sensor dispensing instrument generally designated by thereference numeral 30 and embodying the present invention. The sensordispensing instrument 30 includes an outer housing 32 having an uppercase 34 and a lower case 36. The upper case 34 is pivotable with respectto the lower case 36 in a clam shell fashion so that a sensor pack 38(FIGS. 5-8) can be positioned on an indexing disk 40 within the housing32. With the sensor pack 38 so loaded in the housing 32, a slideactuator 42 on the upper case 34 of the housing 32 can be moved toengage a feed mechanism, generally designated by the numeral 44 (FIG.9B), secured to the inside of the upper case 34 as the slide actuator 42manually is pushed from a standby position (FIGS. 1-3) adjacent a rearend 46 of the upper case 34 toward an actuated or testing position (FIG.4) adjacent a forward or testing end 48 of the upper case 34. The slideactuator 42 also can be moved to place the sensor dispensing instrument30 in a data processing or display mode.

The feed mechanism 44 includes a driver 50 on which is pivotally mounteda knife blade assembly 52, from which extends an indexing disk drive arm54 and on which is mounted a biasing spring 56. As the slide actuator 32is moved toward its actuated position, the driver 50 with the knifeblade assembly 52 thereon moves toward the testing end 48 and a button58 at the distal end of the disk drive arm 54 travels in one of aplurality of radially extending grooves 60A-J in the indexing disk 40such that the indexing disk 40 is not rotated while the driver 50 isbeing moved towards its testing position. As the knife blade assembly 52is being moved toward the testing end 48, a knife blade 62 on the knifeblade assembly 52 pierces a portion of a foil 64 covering one of aplurality of sensor cavities 66A-J, such as the cavity 66F, in a baseportion 68 of the sensor pack 38 in alignment with the knife blade 62. Asensor 70 disposed in the cavity 66A is engaged by the knife blade 62resulting in the knife blade 62 further severing the foil 64 coveringthe sensor cavity 66F and forcing or ejecting the sensor 70 out from thesensor cavity 66F.

After the sensor 70 has been completely ejected from the sensor cavity66F, the driver 50 engages a contact end 72 of a sensor actuator 74 thatis forced against the sensor 70 to thereby maintain the sensor 70 in atesting position projecting out from the testing end 48 (FIG. 4). Thesensor actuator 74 couples the sensor 70 to electronic circuitry on aprinted circuit board 76 disposed in the upper case 34. The circuitry onthe printed circuit board 76 may include a microprocessor or the likefor processing, storing and/or displaying data generated during a bloodglucose test procedure.

Once the blood analyzing test is completed, the slide actuator 42 ismanually retracted in the opposite direction towards its standbyposition adjacent the rear end 46 of the upper case 34 and the sensor 70is released from the contact end 72 of the sensor actuator 74 so thatthe sensor 70 can be removed from the housing 32. The driver 50 issimilarly returned towards the rear end 46 such that the button 58 onthe disk drive arm 54 begins to travel along one of a plurality ofcurvilinearly extending grooves 80A-J, such as groove 80A that isinterconnected to the radially extending groove 60A, resulting in therotation of the indexing disk 40. The rotation of the indexing disk 40also results in the sensor pack 38 being rotated so that the next one ofsensor cavities 66A-J is positioned in alignment with the knife blade 62so that the sensor 70 in the next sensor cavity 66E can be used in thenext blood glucose testing procedure.

As is best seen in FIGS. 1-4 and 9A-C, the upper case 34 and the lowercase 36 of the sensor dispensing housing 32 are complementary, generallyround in shape hollow containers that are adapted to be pivoted withrespect to each other about pivot pins 82 extending outwardly in a rearsection 84 of the lower case 36 into pivot holes 86 in a rear section 88of the upper case 34. The upper case 34 and the lower case 36 aremaintained in their closed configuration as shown in FIGS. 1-4 by alatch 90 that is pivotally mounted in a front or testing section 92 ofthe lower case 36 by pins 94 that extend inwardly into pivot holes 96 inthe latch 90. When the latch 90 is pivoted upwardly, it clips into arecess 98 in a front or testing end section 100 of the upper case 34thereby securing the upper case 34 and the lower case 36 in their closedconfiguration.

The upper case 34 has a recess 102 that extends in its exterior upperwall 104 from the front section 100 to adjacent the rear section 88. Theslide actuator 42 is adapted to be mounted within the recess 102 so thatside extending shoulders 106 slide within opposite grooves 108 along theedges of the recess 102. A slide latch 110 is held in position on theslide actuator 42 by a slide clip 112 that is positioned on the underside of the slide actuator 42, includes a clip 114 that extends throughan opening 116 in the recess 102, clips onto the slide actuator 42 andhas an mode actuator 118. The slide latch 110 includes a plurality ofraised nubs 120 that provides a surface facilitating the movement of theslide latch 110 and the slide actuator 42 by a person using the sensordispensing instrument 30.

The movement of the slide latch 110 places the instrument in one of twooperating modes. In a first or testing mode, the slide latch 110 ispositioned as shown in FIGS. 1, 2 and 4. In a second or data processingmode, the slide latch 110 is slid laterally with respect to the slideactuator 42.

When the slide latch 110 is in its testing mode position, a C-shapedcatch 122 on the lower portion of the slide latch 110 is positioned in alongitudinal extending portion 124 of an opening 126 in the slideactuator 42 (see FIG. 9A). As is described hereinafter, the catch 122projects through a slot 128 in the recess 102 so as to engage a post 130extending upward from the driver 50 as the slide actuator 42 is movedtoward the testing end 48. On the other hand, the C-shaped catch 122 onthe lower portion of the slide latch 110 is disposed in a laterallyextending portion 132 of the opening 126 so that the catch 122 moveswithin a slot 133 as the slide actuator 42 is moved toward the testingend 48 in the data processing mode of the sensor dispensing instrument30. As a result, the catch 122 does not engage the post 130 wheninstrument 30 is in its data processing mode.

The upper case 34 includes a rectangular opening 134 in the rear section88. A lens 136 is positioned in the opening 134 such that a liquidcrystal display unit 138 attached below the lens 136 is visible throughthe lens 136 when the slide actuator 42 is moved away from the rear end46 of the upper case 34. The liquid crystal display unit 138 is coupledto circuits on the printed circuit board 76 via connectors 140 and 142.The displays appearing on the liquid crystal display unit 138 when theinstrument 30 is in its data processing or display mode are controlledby an actuating button 143 and a corresponding pad 144 and an actuatingbutton 146 and a corresponding pad 147 that are disposed in the rear end46. For example, the buttons 143 and 146 can be depressed to view and/orinput the testing information that will be displayed on the liquidcrystal display unit 138.

The upper case 34 also contains a battery holder 148 in which a pair ofbatteries 150 and 152 are disposed. The holder 148 is inserted into aside 149 of the upper case 34 adjacent the front section 100. When soinserted, the batteries 150 and 152 provide power for the electronicswithin the instrument 30 including the circuitry on the printed circuitboard 76 and the liquid crystal display unit 138.

In order to place the instrument 30 in either its testing mode or itsdata processing or display mode, two actuating switches 154 and 156 areprovided. Both of the switches 154 and 156 extend through openings 158and 160 respectively in the recess 102. When the slide latch 110 is inits testing position and the slide actuator 42 is moved toward thetesting end 48, the mode actuator 118 on the slide clip 112 willactivate both of the switches 154 and 156 to thereby place theinstrument 30 in its testing mode. On the other hand, the mode actuator118 only will activate the switch 154 when the slide latch 110 is movedlaterally to its display position and the slide actuator 42 is movedtoward the front end 48. As a result, the instrument 30 will be in itsdisplay mode when only the switch 154 and not the switch 156 is actuatedby the mode actuator 110, but in its testing mode when both of theswitches 154 and 156 are activated.

A block guide 162, the printed circuit board 76, the sensor actuator 74,a housing guide 164, a knife spring 166, the knife assembly 52 and thedriver 50 are held together and secured to the upper case 34 byfasteners 168-171 that extend through those components and into theupper case 34 (see FIG. 9B). In addition, the indexing disk 40 issecured relative to the upper case 34 by being rotatably retained on thehousing guide 164 by a retainer 172 that has a pair of latch arms 174and 176 extending through a central hole 178 in the indexing disk 40 andlatching into an opening 180 in the housing guide 164.

As previously indicated, the driver 50 is advanced toward the front ortesting end 48 of the upper case 34 when the C-shaped clip 122 on theslide latch 110 engages the driver post 130 as the slide actuator 42 isadvanced toward the testing end 48 by a person using the instrument 30.The driver 50 is a molded plastic component having a central recess 182extending longitudinally to an enlarged recess 184 adjacent a forwardedge 186 of the driver 50. A pair of cam projections 188 and 190 extendfrom the forward edge 186 and are adapted to engage the contact end 72of the sensor actuator 74 as the driver 50 is pushed forwarded during atesting procedure. The driver 50 includes opposed recesses 192 extendingoutwardly from the recess 182 in which opposed pivot pins 194 and 196 onthe knife blade assembly 52 are disposed. As a result, the knife bladeassembly 52 is pivotably mounted on the driver 50 such that opposed camfollowers 198 and 200 projecting from opposite sides of the knife bladeassembly 52 can extend positioned through the enlarged recess 184 nearthe forward edge 186 of the driver 52. As will be discussed hereinafter,the cam followers 198 and 200 are adapted to travel along cam surfaces202 and 204 formed on the block guide 162.

The driver 50 also includes the indexing disk drive arm 54 that extendsrearwardly from the driver 50. The indexing disk drive arm 54 is made ofspring type material such as stainless steel so that the button 58affixed at the distal end of the arm 54 can travel in one of theradially extending grooves 60A-J in the indexing disk 40 when the driver50 is being advanced toward the front end 48 or in one of thecurvilinearly extending grooves 80A-J in the indexing disk 40 when thedriver 50 is being returned toward the rear end 46 of the upper case 34.

In order to have the cam followers 198 and 200 extend through the recess184, the biasing spring 56 is positioned on the driver 50 above theknife blade assembly 52 and exerts a downward force on the knife bladeassembly 52. The cam followers 198 and 200 also will be extend throughan enlarged recess 206 of a longitudinally extending slot 208 in theknife spring 166 when the recess 184 is in alignment with the recess206. The knife spring 166 is positioned below the driver 50 and includesspring legs 210 and 212 on either side of the slot 208. The spring leg210 has a ramp portion 214 and the spring leg 216 has a ramp portion216. The cam followers 198 and 200 ride up onto the ramp portions 214and 216 respectively as the driver 50 is being returned toward the rearend 46 to thereby lift the knife assembly 52 and in particularly theknife blade 62 away from the sensor pack 38 disposed on the indexingdisk 40 as the knife assembly 52 is being returned toward the rear end46 with the driver 50.

The driver 50 is mounted on the housing guide 164 which is secured tothe block guide 162 such that the sensor actuator 74 and the printedcircuit board 76 are sandwiched therebetween. The housing guide 164includes a rear frame portion 218 in which the lens 136 and liquidcrystal display unit 138 are disposed. A guide rail portion 220 extendsfrom the rear frame portion 218 toward a front end 219 of the housingguide 164. The guide rail portion 220 has two forwardly extending rails222 and 224 with fastening holes 226-229 located at the outer ends ofthe rails 222 and 224. The fasteners 168-171 extend respectively throughthe holes 226-229. The rail 222 has an upper cam track 230 and the rail224 has an upper cam track 232. The cam track 230 has an opening 234through which the cam follower 198 travels in entering the cam trackformed by the cam tracks 230 and 202 and similarly the cam track 232 hasan opening 236 through which the cam follower 200 travels in enteringthe cam track formed by the cam tracks 232 and 204. A sensor actuatorguide 238 is disposed at the front end 219 of the housing guide 164 andassists in properly maintaining the position of the contact end 72 ofthe sensor actuator 74 relative to the sensor 70 when the sensor 70 isbeing used in test procedure.

The sensor actuator 74 is used to maintain the sensor 70 in its testingposition and to couple the sensor 70 to circuitry on the printed circuitboard 76. The sensor contact end 72 is connected to a circuit contactportion 240 by a pair of contact arms 242 and 244. The contact arms 242and 244 are somewhat flexible being made of plastic molded overstainless steel. The stainless steel portion of the contact arm 242 iscoupled between a sensor contact 246 extending from the sensor contactend 72 and a ring contact 248 in the circuit contact portion 240, thering contact 248 in turn being coupled to circuits on the printedcircuit board 76. Similarly, the stainless steel portion of the contactarm 244 is coupled between a sensor contact 250 extending from thesensor contact end 72 and a ring contact 252 in the circuit contactportion 240, the ring contact 252 in turn being coupled to circuits onthe printed circuit board 76. When one of the sensors 70 is placed intoa testing position (as, for example, shown in FIG. 4), the camprojections 188 and 190 extending from the forward edge 186 of thedriver 50 cam against the contact end 72 of the sensor actuator 74forcing the contact end 72 downwardly such that a post 254 on the sensoractuator 74 is forced against the sensor 70 to maintain the sensor 70 inits testing position. The post 254 also positions the underside of thecontact end 72 the proper distance from the sensor 70 such that thesensor contacts 246 and 250 are deflected the correct amount to insurethat the sensor contacts 246 and 250 make the desired contact with thesensor 70.

As previously indicated, the sensor actuator 74 couples the sensor 70being used in a blood glucose test to circuitry on the printed circuitboard 76. When the printed circuit board 76 is affixed on the blockguide 162, the ring contacts 248 and 252 are coupled to contactsprojecting into corresponding openings 256 and 258 on the printedcircuit board 76. Circuitry on the printed circuit board 76 also iscoupled to the liquid crystal display unit 138 through connectors 140and 142. Circuitry on the printed circuit board 76 in addition needs tobe coupled to a calibration circuitry 260 (FIG. 9C) that is located inthe lower case 36 and that is used to determine information as to thesensor pack 38 being used in the instrument 30. In order to so couplethe calibration circuitry 260 to circuitry on the printed circuit board76, an elastomeric connector 261 is disposed in a channel 262 located ina rear end 263 of the block guide 162.

The elastomeric connector 261 is made of layers of silicon rubberextending from a top edge 261A to a bottom edge 261B with alternatelayers having conductive materials dispersed therein to connect contactson the top edge 261A to contacts on the bottom edge 261B. When the uppercase 34 and the lower case 36 are closed, the connector 261 iscompressed in the direction between the edges 261A and 261B such thatthe contacts along the top edge 261A engage circuitry on the printedcircuit board 76 in the upper case 34 and the contacts along the bottomedge 261B engage the calibration circuitry 260 in the lower case 36.With the elastomeric connector 261 so compressed, low voltage signalscan be readily coupled between the printed circuit board 76 and thecalibration circuitry 260 through the connector 261. In view of the factthat the connector 261 needs to be compressed in the direction betweenthe edges 261A and 261B and at the same time needs to remain in positionin the channel 262 when the instrument 20 is opened, the channel 262 isformed in a serpentine configuration by rounded shaped ridges 264A-Eextending inwardly into the channel 262. As seen in FIG. 9B, the ridges264B and 264D extend inwardly from one side of the channel 262 inbetween the ridges 264A, 264C and 264E that extend inwardly from theopposite side of the channel 262. The serpentine configuration of thechannel 262 enables the somewhat flexible connector 261 to be readilyinserted into and maintained in the channel 262, but also allows theconnector 261 to be compressed when the upper case 34 and the lower case36 are closed.

The block guide 162 includes the cam tracks 202 and 204. The cam tracks202 and 204 are in juxtaposition with respect to the cam tracks 230 and232 so as to form tracks therebetween through which the cam followers198 and 200 respectively travel as the driver 50 is moved towards itstesting position. The cam track 202 has a downwardly extending camsurface 202A that is adjacent a downwardly extending cam surface 230A ofthe cam track 230; the cam track 204 has a downwardly extending camsurface 204A that is adjacent a downwardly extending cam surface 232A ofthe cam track 232; the cam track 202 has an upwardly extending camsurface 202B that is adjacent an upwardly extending cam surface 230B ofthe cam track 230; and the cam track 204 has an upwardly extending camsurface 204B that is adjacent an upwardly extending cam surface 232B ofthe cam track 232. As will be discussed hereinafter, the cam follower198 rides along the cam surfaces 202A and 202B and the cam follower 200rides along the cam surfaces 204A and 204B such that the knife blade 62will protrude through a slot 268 in the block guide 162 between the camtracks 202 and 204 and sever the portion of the foil 64 covering one ofthe sensor cavities 66A-J in alignment with the slot 268 when the sensor70 is being ejected from that cavity into a testing position. When thesensor 70 is so ejected from the cavity, it will project through asensor slot 269 in a sensor guide 270 at the front of the block guide162 that is in alignment with a sensor slot 271 in the latch 90.

Another slot 272 extends rearwardly towards the rear edge 263 of theblock guide 162. The slot 272 is designed such that the indexing diskdrive arm 54 and the button 58 on the distal end of the arm 54 can movethrough the slot 272 in the grooves 60A-J and 80A-J on the indexing disk40 as the driver 50 is moved forward, then backward during a testingprocedure.

The block guide 162 includes mounting holes 274-277 through which thefasteners 168-171 respectively extend in order to mount the block guide162 in proper position in the upper case 34. When the block guide 162 isso positioned in the upper case 34, a flexible battery contact 278 inthe block guide 162 is coupled to the batteries 150 and 152 in thebattery holder 148 through an opening 280 in the battery holder 148.This battery contact 278 is coupled to flexible electrical contacts 282extending from the block guide 162 that make contact with and providepower to the circuitry on the printed circuit board 76. The block guide162 also provides support surfaces 283 and 284 for the contact arms 242and 244 of the sensor actuator 74.

As previously indicated, the indexing disk 40 is mounted on the blockguide 162 by the retainer 172. In so mounting the indexing disk 40, theindexing disk 40 is rotatable with respect to the block guide 162. Whenthe driver 50 is being moved toward the front end 46 of the upper case34 in order to place one of the sensors 70 in a testing position, thebutton 58 on the indexing disk drive arm 54 travels in one of theradially extending grooves 60A-J. As is illustrated with respect to thegroove 60G in FIG. 9B, each of the grooves 60A-J has upwardly inclinedcam surfaces 285 and 286 positioned on opposite sides of a knife slot288. As the button 58 on the indexing disk drive arm 54 travels withinthe groove 60G, the button 58 rides on the cam surfaces 285 and 286 dueto the downward force exerted by the indexing disk drive arm 54 which isflexed slightly upward as the button 58 rides upward on the cam surfaces285 and 286. The cam surfaces 285 and 286 form steps 290 and 292 betweenthe radially extending groove 60G and the interconnected curvilinearlyextending groove 80G. The steps 290 and 292 insure that the button 58will travel only in the radially extending straight grooves 60A-J as thedriver 50 is being moved forward toward the front end 48 and not in theradially extending straight grooves 60A-J when the driver 50 is beingmoved rearwardly toward the rear end 46. This is because the button 58will snap down into the curvilinearly extending groove 80G as it travelspast the steps 290 and 292 and the steps 290 and 292 prevent the button58 from traveling back into the groove 60G as the driver 50 is beingreturned toward the rear end 46. The knife slot 288 in the grooves 60A-Jenable the knife blade 62 to extend through the indexing disk 40 andsever the foil 64 overlying one of the sensor cavities 66A-J that is inalignment and beneath a particular one of the grooves 60A-J.

The grooves 60A-J are straight, radially extending grooves and as aresult, the indexing disk 40 is not rotated as the button 58 travelswithin one of the grooves 60A-J. On the other hand, the button 58 willtravel along one of the curvilinearly extending grooves 80A-J as thedriver 50 is being returned to its standby position or towards the rearend 46. Due to the fact that the grooves 80A-J are curved, the indexingdisk 40 will be rotated as the button 58 is pushed within the grooves80A-J so that the next straight groove (such as the groove 60F) will bein alignment with the next one of the sensor cavities 66A-J when thedriver 50 is returned to its standby position towards the rear end 46.

As is illustrated in FIG. 9B with respect to groove 80G, the grooves80A-J have a downwardly inclined surface 294 such that a step 296 isformed between the groove 80G and the next straight groove 60F. The step296 insures that the button 58 will not travel in the curvilinearlyextending grooves 80A-J as the driver 50 is being moved forward towardthe front end 48. This is because the button 58 will snap down into thestraight groove 60F as it travels past the step 296 and the step 296prevents the button 58 from traveling back into the groove 80G as thedriver 50 is being moved toward the front end 48.

The indexing disk 40 has ten notch retainers 298 extending along theouter peripheral edge of the bottom surface of the indexing disk 40.Each of the notch retainers 298 is adapted to be positioned in one ofthe notches 300 formed along the outer perimeter of the foil 64 and acorresponding one of the notches 302 along the outer perimeter of thebase portion 68 of the sensor pack 38 when the sensor pack 38 ispositioned below the indexing disk 40. When the notch retainers 298 arepositioned in the notches 300 and 302, the sensor pack 38 is retained onthe indexing disk 40 so that the sensor cavities 66A-J are in alignmentrespectively with the grooves 60A-J in the indexing disk 40. Hence, thenotch retainers 298 and the notches 300 and 302 have the dual purpose ofretaining the sensor pack 38 on the indexing disk 40 so that the sensorpack 38 will rotate with the indexing disk 40 and of positioning thesensor pack 38 in proper circumferential alignment relative to theindexing disk 40.

The sensor pack 38 that is positioned below the indexing disk 40 isadapted to house ten sensors 70 with one of the ten sensors 70 in eachof the sensor cavities 66A-J. As is illustrated in FIG. 5 with respectto the sensor 70 in the sensor cavity 66J, each of the sensors 70 has agenerally flat, rectangular shape extending from a front or testing end304 to a rear end 306. The front end 304 is angled so that the front end304 is adapted to puncture an unsevered portion of the foil 64 overlyingthe sensor cavity 66J as the sensor 70 is being forced out of the sensorcavity 66J by the knife blade 62 and is adapted to be placed into bloodthat is being analyzed. The rear end 306 of the sensor 70 includes asmall notch 308 into which the knife blade 62 will become disposed asthe knife blade 62 is ejecting the sensor 70 from the sensor cavity 66J.The notch 308 provides a target area for the knife blade 62 to contactthe sensor 70 and once the knife blade 62 is in contact with the notch308, the sensor 70 becomes centered on the knife blade 62. Contacts 310near the rear end 306 of the sensor 70 are adapted to mate with sensorcontacts 246 and 250 on the contact end 72 of the sensor actuator 74when the sensor 70 is in the testing position illustrated in FIG. 4. Asa result, the sensor 70 is coupled to the circuitry on the printedcircuit board 76 so that information generated in the sensor 70 duringtesting can be stored and/or analyzed.

Each of the sensors 70 is provided with a capillary channel that extendsfrom the front, testing end 304 of the sensor 70 to biosensing orreagent material disposed in the sensor 70. When the testing end 304 ofthe sensor 70 is placed into fluid (for example, blood that isaccumulated on a person's finger after the finger has been pricked), aportion of the fluid is drawn into the capillary channel by capillaryaction so that a sufficient amount of fluid to be tested is drawn intothe sensor 70. The fluid then chemically reacts with the reagentmaterial in the sensor 70 so that an electrical signal indicative of theblood glucose level in the blood being tested is supplied to thecontacts 310 and thereby through the sensor actuator 74 to the printedcircuit board 76.

The sensor pack 38 is formed of the circularly shaped base portion 68and the correspondingly configured foil 64. The sensor cavities 66A-Jare formed as depressions in the base portion 68 with each of the sensorcavities 66A-J adapted to house one of the sensors 70. As illustratedwith respect to the sensor cavity 66A in FIG. 6, each of the sensorcavities 66A-J has a bottom support wall 312 that extends from an innerend 314 to an outer end 316 of the sensor cavity 66A. The support wall312 is inclined or sloped slightly upward as it extends from the innerend 314 to the outer end 316. This sloping of the support wall 312results in the sensor 70 being raised slightly as it is being ejectedfrom the sensor cavities 66A-J so that it will avoid or pass above thatportion of the heat seal affixing the foil 64 to the base portion 68along the outer peripheries of the foil 64 and the base portion 68.

Each of the sensor cavities 66A-J is in fluid communication with acorresponding one of desiccant cavities 318A-J. Each of the desiccantcavities 318A-J is formed of a small depression in the base portion 68adjacent the corresponding one of the sensor cavities 66A-J. Desiccantmaterial is disposed in the desiccant cavities 318A-J in order to insurethat the sensor cavities 66A-J are maintained at an appropriate humiditylevel so that the reagent material in the sensor 70 disposed in theparticular sensor slot 66A-J is not adversely affected prior to beingused. The desiccant material might be in the form of a small bag orround bead of material or any other form that can be readily disposed inthe desiccant cavities 318A-J. The amount of such desiccant materialplaced in each of the desiccant cavities 318A-J will be dependent on theamount that is required to maintain the sensor cavities 66A-J in adesiccate state. One type of desiccant material that could be used issold under the trademark NATRASORB and is available in powder, pelletand bead forms.

The notches 302 are formed along the outer peripheral edge of the baseportion 68. When the foil 64 is sealed to the base portion 68, thenotches 300 along the outer peripheral edge of the foil 64 will be inalignment with the notches 302 to thereby form an integral series ofnotches along the outer peripheral edge of the sensor pack 38. Each ofthe notches formed by the notches 300 and 302 is associated with one ofthe sensor cavities 66A-J in the base portion 68 such that when thesensor pack 38 is mounted on the indexing disk 40 with the notchretainers 298 disposed in the notches 300 and 302, the sensor cavities66A-J will each be in proper alignment with an individual one of thestraight grooves 60A-J in the indexing disk 40.

The foil 64 is adapted to cover the top of the base portion 68 and beaffixed to the base portion by heat sealing along the entire outerperipheral edge of the foil 64 to the outer peripheral edge of the baseportion 68. The foil 64 also is heat sealed about the entire perimeterof each set of the sensor retaining cavities 66A-J and the desciccantcavities 318A-J to seal the sensor retaining cavities 66A-J and thedesiccant cavities 318A-J such that the individual sensors 70 aremaintained in a desiccated state and isolated from each other. As aresult, the opening of one of the sensor cavities 66A-J will not affectthe desiccated state of any of the other sensor cavities 66A-J. The foil64 may be made of any material that will adequately seal the sensorcavities 66A-J and the desiccant cavities 318A-J while providing amaterial that will can be really severed by the knife blade 62 andpierced by the sensor 70 as it is being pushed out from the sensorcavities 66A-J. One type of foil that can be used for the foil 64 isAL-191-01 foil distributed by Alusuisse Flexible Packaging, Inc.

As is illustrated in FIG. 8, the base portion 68 includes a label area320 on its underside inwardly of the sensor cavities 66A-J. A conductivelabel 322 is positioned in this label area 320 and provides calibrationand production information that can be sensed by the calibrationcircuitry 260.

The calibration circuitry 260 is located in the lower case 36. Thecalibration circuitry 260 as well as an upper plate 324, an adhesivering 326 and a pad 328 are held in position in the lower case 36 by aretainer clip 330 that extends through an opening 332 in the lower case36 and into an opening 334 in the upper plate 324. The upper plate 324has an inner metal region 338 with the remaining outer portions 340being plastic. The calibration circuitry 260 is maintained in propercircumferential position with respect to the upper plate 324 by theadhesive ring 326 such that probes 342 extending upperwardly from thecalibration circuitry 260 are in alignment with and extend through holes344 in the inner metal region 338 about the opening 334.

When the sensor dispensing instrument 30 is closed with the lower case36 latched to the upper case 34 by the latch 90, the probes 342 makecontact with the conductive label 322 located in the label region 320 ofthe sensor pack 38 being used in the sensor dispensing instrument 30. Inorder to assure that the probes 342 press against the conductive label322 with an appropriate force, the pad 328 is positioned below theflexible calibration circuitry 260 and provides a cushion so that theprobes 342 can move independently with respect to each otherparticularly as the sensor pack 38 is being rotated by the indexing disk40. As a result, information, such as calibration and production data,contained on the label 322 can be transmitted via the probes 342 to thecalibration circuitry 260 which in turn couples the data to thecircuitry on the printed circuit board 76 via the elastomeric connector261. The information then can be displayed on the liquid crystal displayunit 138 through the lens 136 when the sensor dispensing instrument 30is placed in its display mode by the movement of the slide latch 110laterally and forward movement of the slide actuator 42 toward the frontend 48.

In order for the sensor dispensing instrument 30 to be used by a personfor testing of blood glucose, the instrument 30 needs to be opened sothat the sensor pack 38 can be inserted in proper position on theindexing disk 40. The instrument 30 is opened by moving the latch 90away from its latching position in the recess 98 in the front section100 of the upper case 34. With the latch 90 so released, the lower case36 can be swung away from the upper case 34 about the pivot pins 82. Anypreviously used sensor pack 38 can be removed from its position on theindexing disk 40 and a new sensor pack 38 can be positioned on theindexing disk 40 by positioning the notch retainers 298 in the notches300 and 302 along the outer periphery of the sensor pack 38. With thesensor pack 38 so positioned on the indexing disk 40, each of the sensorcavities 66A-J will be in alignment beneath the knife slot 288 in one ofthe straight radially extending grooves 60A-J.

With the sensor pack 38 positioned on the indexing disk 40, the lowercase 36 can be swung toward the upper case 34. The latch 90 is pivotedon the pins 94 and is latched in the recess 98 in the front section 100of the upper case 34 such that the lower case 36 is closed against theupper case 34. When the lower case 36 and the upper case 34 are latchedtogether, the probes 342 projecting from the calibration circuitry 260through the holes 344 in the upper plate 324 engage the label 322located in the label area 320 of the sensor pack 38. As a result,information contained on the label 322 with respect to the sensor pack38 is provided to the circuitry on the printed circuit board 76 via theconnector 261. In addition, the position of the sensor pack 38 can bedetected by the probes 342 so that the rotational position of the sensorpack 38 can be detected as the sensors 70 in the sensor pack 38 are usedfor testing purposes.

With the upper case 34 and the lower case 36 latched together, the slidelatch 110 can be manipulated to place the sensor dispensing instrument30 in either its display or data processing mode or its testing mode.For example, the slide latch 110 can be moved laterally with respect tothe longitudinal axis of the instrument 30 to place the instrument 30 inits display mode. As the slide latch 110 is moved laterally, theC-shaped catch 122 is moved into the laterally extending portion 132 ofthe opening 126 in the slide actuator 42. The movement of the slideactuator 42 toward the front end 48 results in a cam surface 346 on themode actuator 118 on the side of the slide clip 112 contacting anddepressing an actuator button 348 of the on/off switch 154 extendingthrough the opening 158 to thereby close the normally open switch 154.With the slide latch 110 moved laterally, the mode actuator 118 will notcontact an actuator button 350 of the on/off switch 156 that extendsthrough the opening 160. The closing of the on/off switch 154 withoutthe actuation of the on/off switch 156 results in the sensor dispensinginstrument 30 being activated into its display mode. During this forwardmovement of the slide actuator 42 toward the front end 48, the C-shapedcatch 122 will move in the slot 133 so that it will not engage the post130 extending from the driver 50. As a result, the driver 50 will remainin its standby position toward the rear end 46 of the upper case 34.

As the slide actuator 42 is moved toward the front end 48, the slideactuator 42 will be moved away from the opening 134 in the rear section88 of the upper case 34 and the liquid crystal display unit 138 will bevisible through the lens 136. Information concerning the sensor pack 38and the tests that have been conducted can be displayed on the liquidcrystal display unit 138. The information that is displayed can bedetermined by the actuation of the buttons 143 and 146 projecting fromthe rear end 46 of the upper case 34. The buttons 143 and 146 also areused to input information into the circuitry on the printed circuitboard 76 in accordance with the displays on the liquid crystal displayunit 138. As this information is being displayed or inputted, an audibleindicator is selectively annunciated by a piezo alarm 352 locatedadjacent the switches 154 and 156 in the upper case 34.

When the user of the sensor dispensing instrument 30 has completedobtaining information or inputting data, the slide actuator 42 isreturned toward the rear end 46 of the upper case 34 by sliding it inthe recess 102 formed in the upper wall 104 of the upper case 34. Afterthe mode actuator 118 has passed the actuator button 348, the actuatorbutton 348 will no longer be depressed and the on/off switch 154 will bereturned to its normal open condition. The instrument 30 will then be inits off or standby condition. Once the slide actuator 42 has beenreturned to its full retracted position, the slide actuator 42 will beheld in that position by a detent 354 projecting from the recess 102adjacent the rear end of the slot 133. With the slide actuator 42 in itsfully retracted position, the slide actuator 42 will again cover thelens 136 for the liquid crystal display unit 138 and the slide latch 110can be moved laterally back to its normal position as illustrated inFIG. 1 of the drawings.

The primary use of the sensor dispensing instrument 30 is in connectionwith a blood glucose test. When such a test is to be conducted, a userof the instrument 30 can push against the nubs 120 on the slide latch110 in order to slide the slide actuator 42 in the recess from itsstandby position near the rear end 46 toward the front or testing end48. As the slide actuator 42 is moved toward the testing end 48, the camsurface 346 on the mode actuator 118 on the side of the slide clip 112contacts and depresses the actuator button 348 of the on/off switch 154extending through the opening 158 and the actuator button 350 of theon/off switch 156 extending through the opening 160. The depression ofboth of the actuator buttons 348 and 350 by the mode actuator 118 closesboth of the on/off switches 154 and 156. The closing of both of theon/off switches 154 and 156 results in the sensor dispensing instrument30 being activated into its testing mode.

As the slide actuator 42 is moved toward the front end 48, the C-shapedcatch 122 will move in the slot 128 so that it will be in engagementwith the post 130 extending from the driver 50. As a result, the driver50 will be moved along with the slide actuator 42 toward the front end48. When the driver 50 was in its standby position toward the rear end46, the cam follower 198 was extended through the enlarged recess 184 inthe driver 50, the enlarged recess 206 in the knife spring 166, and theopening 234 in the housing guide 164 and similarly the cam follower 200was extended through the enlarged recess 184 in the driver 50, theenlarged recess 206 in the knife spring 166, and the opening 236 in thehousing guide 164. Consequently, the cam followers 198 and 200 wereposed at the rear end of the cam surfaces 202A and 204A respectively ofthe cam tracks 202 and 204.

As the driver 50 is moved toward the front end 48 with the slideactuator 42, the cam followers 198 and 200 respectively will travelalong the downwardly extending cam surfaces 202A and 204A such that theknife blade 62 will dip through the slot 268 in the block guide 162between the cam tracks 202 and 204 and the knife slot 288 in thestraight groove, for example, the groove 60J, on the indexing disk 40 inalignment with the slot 268. The continued downward movement of theknife blade 62 as the cam followers 198 and 200 travel along the camsurfaces 202A and 204A respectively results in the knife blade 62beginning to sever a portion of the foil 64 that is covering theparticular one of the sensor cavities 66A-J, for example, the sensorcavity 66J, that is in alignment with the groove 60J on the indexingdisk 40.

As the knife blade 62 severs the foil 64, it also dips further into thesensor cavity 66J and engages the notch 308 at the rear end 306 of thesensor 70 housed in the sensor cavity 66J. The further movement of thedriver 50 and thereby the knife blade 62 toward the front end 48 causesfurther severing of the foil 64 over the sensor cavity 66J and the frontend 304 of the sensor 70 will begin to ride upwardly on the inclinedbottom support wall 312. As this is occurring, the cam follower 198 willstart to travel along the upperwardly inclined cam surface 202B and thecam follower 200 will start to travel along the upperwardly inclined camsurface 204B such that the knife blade 62 will tend to lift the sensor70 as it is being ejected from the cavity 66J with the front end 304piercing through the portion of the foil 64 overlying the sensor cavity66J. The front edge 304 of the sensor 70 has a pointed, biased geometryso that the front edge 304 of the sensor 70 cuts an exit hole throughthe foil 64 rather than merely stretching it as the sensor 70 isbursting through the foil 64 covering the sensor cavity 66J. The liftingof the front end 304 due at least in part to the upwardly inclinedsupport wall 312 enables the front end 304 of the sensor 70 to avoid theheat seal around the outer peripheries of the foil 64 and the baseportion 68 of the sensor pack 38; otherwise the heat seal couldinterfere with the ejection of the sensor 70 from the sensor cavity 66J.

The continued forward movement of the driver 50 with the slide actuator42 will result in the sensor 70 being completely ejected from the sensorcavity 66J. Once the sensor 70 has been ejected from the sensor cavity66J, the sensor 70 is guided into the sensor slot 269 in the sensorguide 270 and the aligned sensor slot 271 in the latch 90 until thefront or testing end 304 of the sensor 70 is projecting out from thefront end 48 of the upper case as is illustrated in FIG. 4. As thesensor 70 is being guided through the sensor slots 269 and 271, the camprojections 188 and 190 projecting from the forward edge 186 of thedriver 50 engage the contact end 72 of the sensor actuator 74 therebyforcing the contact end 72 downwardly along the sensor actuator guide238 toward the sensor 70. The post 254 extending from the contact end 72is forced against the sensor 70 to maintain the sensor 70 in the sensorguide 270 and projecting through the sensor slots 269 and 271. Inaddition, flexible sensor contacts 246 and 250 projecting from thecontact end 72 on either side of the post 254 make electrical contactwith the contacts 310 on the sensor 70 so that the contacts 310 on thesensor 70 are coupled to the circuits on the printed circuit board 76through the contacts 246 and 250, the contact arms 242 and 244 of thesensor actuator 74, and the ring contacts 248 and 252 on the circuitcontact portion 240 of the sensor actuator 74. The engagement of thepost 254 against the sensor 70 not only clamps the sensor 70 in itstesting position, but also assures that the sensor contacts 246 and 250make the desired contact with the sensor contacts 310 by positioning thecontact end 72 of the sensor actuator 74 the appropriate distance fromthe sensor 70.

As the driver 50 is being moved forward toward the front end 48 of theupper case 34, the button 58 at the distal end of the indexing diskdrive arm 54 will travel through the slot 272 in the block guide 162 andalong the straight groove 60E in the indexing disk 40 (i.e., the groovediametrically opposite to the groove 60J). The indexing disk 40 will notbe rotated as the button 58 travels along the cam surfaces 285 and 286in the groove 60E and past the steps 290 and 292 into the interconnectedcurvilinearly groove 80E.

Once the sensor 70 is in its testing position and the slide actuator 42and the driver 50 have been moved to their forward or testing position,the button 58 is positioned in the innermost portion of thecurvilinearly groove 80E and the cam followers 198 and 200 arepositioned forward of the ramp portions 214 and 216 of the knife spring166. The testing end 304 of the sensor 70 then can be placed into fluid,such as blood that is accumulated on a person's finger after the fingerhas been pricked. The fluid is absorbed into the sensor 70 andchemically reacts with the reagent material in the sensor 70 so that anelectrical signal indicative of the blood glucose level in the bloodbeing tested is supplied to the contacts 310 and thereby through thesensor actuator 74 to the printed circuit board 76.

Once the blood analyzing test is completed, the slide actuator 42 ismoved away from the front end 48 toward the rear end 46 of the uppercase 34 by a user of the instrument 30 pushing on the nubs 120projecting from the slide release 110. As the slide actuator 42 is movedtoward the rear end 46, the cam projections 188 and 190 projecting fromthe forward edge 186 of the driver 50 are moved away from engaging thecontact end 72 of the sensor actuator 74 so that the contact end 72 ismoved away from the sensor 70 due to the resiliency in the contact arms242 and 244 as they extend forward of the support surfaces 283 and 284on the block guide 162. With the post 254 no longer forced against thesensor 70, the sensor 70 that was used in the glucose test can beremoved from the sensor slots 269 and 271 and discarded.

As the driver 50 is being moved away from the front end 48, the camfollower 198 on the knife assembly 52 will ride up the ramp portion 214onto the spring leg 210 of the knife spring 166 and the cam follower 200on the knife assembly 52 will ride up the ramp portion 216 onto thespring leg 212 of the knife spring 166. The knife spring 166 pivots theknife assembly 52 upward about the pivot pins 194 and 196 so that theknife blade 62 is displaced from the indexing disk 40 and the sensorpack 38 mounted therebelow. With the knife blade 62 so displaced fromthe indexing disk 40, the indexing disk 40 can be rotated in order toplace another one of the sensor cavities 66A-J in alignment with theslot 268 in the block guide 162.

In this regard, the retraction of the slide actuator 42 toward the rearend 46 forces the button 58 on the indexing disk drive arm 54 to travelalong the downwardly inclined surface 294 in the groove 80E. Thismovement in the curved groove 80E causes the disk 40 to be rotated suchthat the next straight groove 60I will be moved into alignment under theslot 272 in the block guide 162 as the button 58 enters the nextstraight groove 60D. Once the slide actuator 42 reaches its fullyretracted position past the detent 354, the biasing spring 56 forces theknife blade assembly 52 downwardly so that the cam follower 198 isextended through the enlarged recess 184 in the driver 50, the enlargedrecess 206 in the knife spring 166, and the opening 234 in the housingguide 164 and similarly the cam follower 200 is extended through theenlarged recess 184 in the driver 50, the enlarged recess 206 in theknife spring 166, and the opening 236 in the housing guide 164. As aresult, the cam followers 198 and 200 are posed at the rear end of thecam surfaces 202A and 204A respectively of the cam tracks 202 and 204 sothat another one of the sensors 70 in the sensor pack 38 can be ejectedfrom the sensor pack 38 and used in another testing procedure.

While the invention has been described with reference to details of theillustrated embodiment, these details are not intended to limit thescope of the invention as defined in the appended claims. For example,the instrument 30 can be used for testing fluids other than bloodglucose. In fact, the instrument 30 can be used in connection withanalyzing any type chemistry fluid that can be analyzed by means of areagent material.

What is claimed and desired to be secured by Letters Patent of theUnited States is:
 1. A sensor dispensing instrument for handling of aplurality of fluid sensors comprising:an outer housing; a sensor packhaving a plurality of sensor retaining means, each of which sensorretaining means being adapted to accommodate one of said plurality offluid sensors and is at least partially enclosed by enclosure means;indexing means mounted in said housing, said sensor pack being disposedon said indexing means so as to be advanced as said indexing means isadvanced such that one of said sensor retaining means is disposed in afeed position; a driver means disposed in said housing and movablebetween a first position and a second position, said driver means havinga cutting means pivotally mounted thereon and riding on a cam trackdisposed in said housing as said driver means is moved from said firstposition towards said second position whereby said cutting means travelsalong said cam track so as to pivot towards one of said plurality ofsensor retaining means to thereby pierce said enclosure means to enterinto said one of said plurality of sensor retaining means that is insaid feed position and to engage said sensor to advance said sensor fromsaid sensor retaining means into a testing position; indexing drivemeans associated with said driver means and said indexing means toadvance said indexing means as said driver means is returned to saidfirst position so as to position another one of said plurality of sensorretaining means in said feed position as said driver means is beingreturned to said first position; and lifting means disposed in saidhousing relative to said cam track for lifting said cutting means awayfrom said sensor pack as said driver means is being returned towardssaid first position.
 2. A sensor dispensing instrument as set forth inclaim 1 wherein said cutting means severs said enclosure means as saidcutting means enters said one of a plurality of said sensor retainingmeans and forces said sensor through said enclosure means from saidsensor retaining means, said sensor being guided into said testingposition by guide means disposed within said housing.
 3. A sensordispensing instrument as set forth in claim 1 including holding means tomaintain said sensor in said testing position and including holdingcontact means on said holding means and wherein said sensor includessensor contacts and wherein said driver means includes cam meansengaging said holding means as said sensor is disposed in said testingposition such that said sensor is maintained in said testing positionwith said holding contact means being coupled to said sensor contacts.4. A sensor dispensing instrument as set forth in claim 3 wherein saidsensor dispensing instrument includes data processing means coupled tosaid holding contact means through said holding means to process dataobtained from said sensor.
 5. A sensor dispensing instrument as setforth in claim 2 wherein each of said sensor retaining means includes asensor cavity and a desiccant cavity, said desiccant cavity of each ofsaid sensor retaining means being in fluid communication with saidsensor cavity of said sensor retaining means.
 6. A sensor dispensinginstrument as set forth in claim 5 including desiccant material in eachof said plurality of desiccant cavities so that each of said pluralityof sensor retaining means is maintained in a desiccate state.
 7. Asensor dispensing instrument as set forth in claim 1 wherein said sensorpack includes a base portion in which said sensor retaining means areformed, wherein said enclosure means is a foil that is heat sealed onsaid base portion about an outer peripheral edge of said base portionand about each of said sensor retaining means to seal said sensorretaining means with said sensors therein, and wherein each of saidsensor retaining means includes a sensor cavity having a support wall onwhich said sensor is disposed that extends in a radial direction fromadjacent the peripheral edge of said base portion toward a center ofsaid base portion, said support wall having a sloped portion that issloped toward said foil in a direction toward said peripheral edge ofsaid base portion such that as said sensor is advanced along said slopedportion of said support wall of said sensor retaining means as saidsensor is forced through said foil and out of said sensor retainingmeans said sensor avoids said heat seal of said foil to said baseportion.
 8. A sensor dispensing instrument as set forth in claim 1wherein said sensor includes sensor contacts, said sensor dispensinginstrument includes contact means with positioning means thereon, andsaid driver means includes a cam means engaging said contact means assaid sensor is disposed in said testing position such that saidpositioning means is forced against said sensor to maintain said sensorin said testing position and assures said contact means are coupled tosaid sensor contacts.
 9. A sensor dispensing instrument as set forth inclaim 8 wherein said sensor dispensing instrument includes dataprocessing means coupled to said contact means to process data obtainedfrom said sensor.
 10. A sensor dispensing instrument as set forth inclaim 1 wherein said indexing means is generally circular in shape andincludes a plurality of first grooves extending radially from aperipheral edge of said indexing means and a plurality of secondgrooves, one of said second grooves being associated with each of saidfirst grooves, said second grooves extending curvilinearly with respectto said first groove with which it is associated, said driver meanshaving a pack drive means that travels along one of said first groovesas said driver means is moved from said first position to said secondposition and travels along said second groove associated with said firstgroove to thereby rotate said indexing means as said driver means isreturned toward said first position from said second position.
 11. Asensor dispensing instrument as set forth in claim 10 wherein each ofsaid first grooves includes a ramp means, said pack drive means travelsalong said ramp means as said driver means is moved from said firstposition toward said second position, said ramp means preventing saidpack drive means from traveling along said first groove as said drivermeans is being returned towards said first position from said secondposition.
 12. A sensor dispensing instrument as set forth in claim 11wherein said indexing means is rotatably mounted in said housing andincludes pack holding means along its outer peripheral edge and saidsensor pack includes sensor holding means adapted to engage said packholding means to maintain said sensor pack on said indexing means suchthat said sensor pack will rotate with said indexing means.
 13. A sensordispensing instrument as set forth in claim 12 wherein said sensorholding means includes notches along an outer peripheral edge of saidsensor pack into which notches said pack holding means are disposed whensaid sensor pack is disposed on said indexing means, said notches arepositioned on said sensor pack with respect to each of said plurality ofsensor retaining means such that one of said plurality of sensorretaining means is positioned in said feed position when said drivermeans is returned to said first position.
 14. A sensor dispensinginstrument as set forth in claim 13 wherein said notches and said sensorretaining means are equally spaced on said sensor pack.
 15. A sensordispensing instrument as set forth in claim 1 wherein each of saidsensor retaining means includes a sensor cavity and a desiccant cavityin fluid communication with said sensor cavity of said sensor retainingmeans, said sensor cavity having a support wall on which said sensor isdisposed that extends in a radial direction from adjacent a peripheraledge of said sensor pack toward a center of said sensor pack, saidsupport wall having a sloped portion that is sloped toward saidenclosure means in a direction toward said peripheral edge of saidsensor pack such that said sensor is advanced along said sloped portionof said support wall of said sensor retaining means as said sensor isadvanced from sensor retaining means.
 16. A sensor dispensing instrumentfor handling of a plurality of fluid sensors comprising:an outer housingincluding first and second case portions pivotable with respect to eachother between open and closed states; a sensor pack having a pluralityof sensor retaining means, each of which sensor retaining means beingadapted to accommodate one of said plurality of fluid sensors and is atleast partially enclosed by enclosure means, said sensor pack beingdisposed in said first case portion of said housing such that one ofsaid sensor retaining means is disposed in a feed position; a drivermeans disposed in said housing, having a cutting means and movablebetween a first position and a second position such that said cuttingmeans is moved towards one of said plurality of sensor retaining meansthat is in said feed position as said driver means is moved towards saidsecond position in order for said cutting means to pierce said enclosuremeans, engage said sensor disposed in said sensor retaining means andadvance said sensor from said sensor retaining means into a testingposition as said driver means is moved from said first position towardsaid second position; label means on said sensor pack having datathereon; circuit means disposed in said first case portion of saidhousing; calibration means disposed in said second case portion of saidhousing for contacting said label means in order to obtain datatherefrom; and an elastomeric connector that is disposed in a serpentineconfigured channel for connecting said circuit means to said calibrationmeans when said first and second case portions are in said closed state,said connector being maintained in said channel when said first andsecond case portions are in said open state and is compressed betweensaid circuit means and said calibration means when said first and secondcase portions are in said closed state.
 17. A sensor dispensinginstrument as set forth in claim 16 wherein said channel includesalternating opposed ridges extending inwardly from opposite side edgesof said channel.